chore(wasm): remove unnecessary conditional statement

[btea]

Description

Buffer.from(string[, encoding]) is supported in node 5.10.0 version, earlier than atob. Therefore, I think this if statement is unnecessary.

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[sapphi-red]

This wasmHelper function is included in the output bundle and could run in browser or node (SSR). Because Buffer doesn't exist in browsers we'll need to have a fallback.
Ideally we should use a different function for non-SSR and SSR (#8882).

BTW fetch supports data URI so we can use fetch for data uri as well in browsers.

[btea]

OK, I got it, thank you for your explanation. 👍